STUDY OF THE PRO-INFLAMMATORY ACTIVITY OF ENTERIC GLIA ON INTESTINAL EPITHELIAL CELLS

Background:The enteric nervous system (ENS) is the intrinsic innervation of the gastrointestinal tract. Enteric glia (EG) plays important roles, such as maintaining the intestinal epithelial barrier (IEB) by stimulating the expression of occludin and ZO-1. However, its role in the context of inflammation will depend on its state, which can be either "activated," where it maintains homeostasis, or "reactive," where it exhibits a deleterious response to the integrity of the IEB, with increased GFAP and the release of S100β and other cytokines. In inflammatory bowel diseases (IBDs), enteric glia exacerbates the inflammatory condition.This study aims to characterize the activity of EG in its active and reactive states, its pro-inflammatory activity, and its influence on intestinal epithelial cells. Methodology: Investigate in vitro how EG (rat EG cell line, CRL2690) responds to LPS 1µg/ml after 24h, 3 and 6 days, evaluating glial markers, inflammatory signaling pathways, and the release of pro-inflammatory cytokines. Evaluate the influence of treatments with EG conditioned medium and LPS in Caco-2 or RKO intestinal epithelial cells.Results: Our preliminary results indicate that EG presents an increase in S100β release, and GFAP and NFκB-P65 protein levels when treated with LPS 1µg/ml for 72 hours. WB and immunofluorescence assays do not indicate a change in cx43 under different LPS treatment times. Treatment of Caco-2 with LPS causes disorganization of the tight junctions, which appears to be mitigated in co-culture with EG. RKO cells were treated with a conditioned medium from GE-LPS24h or GE-LPS72h and did not alter proliferation. Conclusions: Initial data suggest a different phenotype of EG in short and long exposure times to LPS, with reactivity and pro-inflammatory activity after 3 days of exposure to LPS but not after 6 days. This study will help us to understand the role of EG in IBDs and how its inhibition should be considered for IBDs treatment.